All columns are not displaying after extracting Lead data through API

I am extracting lead data through API calls But after extraction all columns are not displaying, some of the columns are missing likeAccount Owner Email Address, Account Owner First Name, Account Owner Last Name, Company Notes etc.

SOAP API's method getMultipleLeads retrieves one or multiple lead records from Marketo, with all field values for the built-in and custom fields for a lead identified by the provided key (LeadKey). If I am following you correctly the fields mentioned belong to Account, not Lead.

System fields are not accessible via the SOAP API. Specifically, any field that is read-only will not be accessible via the SOAP API. The solution is to create custom fields in Marketo, and use a Smart Campaign to copy the data from the system field into the custom field. The custom field can then be accessed via the SOAP API.

We send back all the fields that are available for use in a Form. All the fields that you list as missing are ones that you would never put on a Form. Also, the values returned by the API are the API name, which may be different from the Friendly name. You can obtain the mapping of Friendly names to API names by downloading the CSV from Admin->Field Management->Export Field Names

The workaround for this is to use a campaign to populate custom fields as per Jep's suggestion